Make game creation wizard fit viewport without scrolling

Replace scrollable form content with responsive sizing that
automatically scales elements to fit available viewport height.

CSS improvements:
- Disable scrolling: overflow-y:auto → overflow:hidden in form-content
- Implement fluid typography with clamp() for titles, labels, buttons
- Add responsive spacing using clamp() for margins and padding
- Scale progress dots from 10px-16px based on viewport height
- Reduce button dimensions (60px min-width, 36px min-height)
- Enable element shrinking with flex-shrink:1 and min-height:0

Component cleanup:
- Remove auto-focus useEffect from Player1/2/3Step components
- Prevents unwanted layout shifts on wizard mount

Benefits:
- All elements visible without scrolling
- Responsive design scales smoothly across viewport sizes
- Cleaner UX with no scrollbars in form wizard
- Better space utilization on small screens

src/components/new-game/Player3Step.tsx

@@ -14,13 +14,6 @@ export const Player3Step = ({ playerNameHistory, onNext, onCancel, initialValue
   const [filteredNames, setFilteredNames] = useState(playerNameHistory);
   const inputRef = useRef<HTMLInputElement>(null);
 
-  useEffect(() => {
-    const el = inputRef.current;
-    if (el) {
-      el.focus();
-    }
-  }, []);
-
   useEffect(() => {
     if (!player3) {
       setFilteredNames(playerNameHistory);